my suggestion is to not grow with CFL's unless you absolutely have to. Your bud is probably going to be super fluffy and not as good of quality. Its a lot better idea to just wait and save up money to buy a 400 watt HPS or Metal Hylide for 2 plants.
My suggestion would be to learn what you're talking about before you post. Just because you saw some crappy buds grown by a clueless newb under CFLs doesn't mean CFLs are worthless.
Fact of the matter is CFLs produce a better
quality of light than HID lamps do, HID lamps produce a greater
quantity of light.
Learn how to use a tool correctly before you claim the tool doesn't work. To use CFLs you have to not try to grow monster trees in huge pots. You need to keep the plants compact and close to the bulbs. Training is almost manditory under CFLs.
Also consider, if you're growing with a single HID bulb and it goes out for whatever reason (breaks, shorts, just stops working, etc.) your grow is at an end until you fork out some more cash for a new bulb. Grow with a couple CFLs and lose one, big fucking deal...grow is still on and you've only lost a couple lumens/points of light. And CFLs are available at your local Wal-Mart for super cheap.
Not to mention the fact that (here comes your clue)
this is the CFL forum, not the HID forum.
*edit*
And then you could even run a few of those CFL's so that you get a mixed spectrum of light
This is actually a great idea if you can do it (ie. afford it, take care of heat issues, make it stealthy, etc.). I plan to add a small (70-150W) HPS to my flower box at some point. The two bulb types compliment each other very well. For the ultimate (IMO) use a small MH, a small HPS, and several 42W CFLs, some blue and some red spectrum. Many points of light, grow not totally dependant on any one bulb, full spectrum of light, floro light quality, HID canopy penatration...just don't get much better than that IMO.
Sorry for sounding like a dick, just hit on a sore spot. Sometimes "just use a HID!" isn't the answer.